We have several SPA504G Phones working fine with asterisk. We use Alert-Info to alert the user of external calls.
We can use all the built-in ring tones but not the custom ring tones. There are some Discussions of this topic.
Our problem now is that we want to use a new SPA525G2 phone in this enviroment. When we send the same SIP header to this phone, the phone does not even ring. Can anyone tell use how to use Alert-Info: on a SPA525G2 to change the ring tone?